Refugees who try to reach Australia by boat will be banned from ever visiting the country, Prime Minister Malcolm Turnbull has said.

He announced plans to ratchet up his tough policy against asylum seekers, saying: "You need the clearest of clear messages."

A previous government introduced a policy on July 19 2013, banning refugees who arrive by boat from Indonesian ports after that date from ever being resettled in Australia.

Under legislation to be unveiled next week, thousands of asylum seekers who have returned to their homelands in the Middle East, Africa and Asia would be banned for life from ever travelling to Australia as tourists, to do business or as an Australian's spouse.

Mr Turnbull said: "This is a battle of will between the Australian people, represented by their government, and these criminal gangs of people smugglers. You should not under-estimate the scale of the threat."

Australia has paid the poor Pacific nations of Nauru and Papua New Guinea to keep asylum seekers in camps since the 2013 policy came into force.

The new policy would apply to all asylum seekers who have attempted to reach Australia since July 19 2013.

Immigration minister Peter Dutton said asylum seeker children would be exempt from the visa ban and he would have discretion to make exceptions for adults in cases where to do so was in the public interest.

More than 51,000 asylum seekers arrived in Australian waters by boat during the six years the former centre-left Labor Party government was in power from 2007 until 2013. More than 20,000 arrived in 2013.

No boat smuggling operation has succeeded in delivering asylum seekers to Australia since July 2014 under Mr Turnbull's conservative government.

But human rights groups have accused Australia of abrogating its responsibilities to refugees as a signatory to the United Nations Refugee Convention.

Labor spokesman Brendan O'Conner said the opposition would have to read the legislation before deciding whether it would support it in the Senate where the government does not hold a majority of seats.

"With any legislation you want to look at it, see whether in fact it is fair and reasonable and is consistent with our own commitments internationally," he O'Connor said.